Method and the machine for stretching dressed fur or leather skins



y 1959 I s. KREME 2,884,777

METHOD AND THE MACHINE STRE ING DRESSED FUR OR LEA SKI Filed June 28, 1954 2 Sheets-Sheet 1 FlG.l

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May 5, 1959 5 KREMEN 2,884,777

METHOD AND THE MACHINE FOR STRETCHING DRESSED FUR OR LEATHER SKINS Filed June 28, 1954 2 Sheets-Sheet 2 IN VEN TOR.

United States Patent METHOD AND THE MACHINE ,FOR STRETCHING DRESSED FUR OR LEATHER SKINS The object of this invention is to provide a convenient 5 method and means for uniform two-directional stretching of fur or leather skins that have already been dressed,

without plucking, crushing or disarranging the hair of the fur skins or damaging the fine grain ofthe leather skins.

Another object of this invention is to provide a means for stretching flat materials, without marking, stretching or damaging the showy surface of those materials.

Other objects of this invention will be apparent from the disclosures in this specification and the accompanying drawings.

The accompanying drawings illustrate only the novel features of this machine, omitting the details of construction that are common technical knowledge.

Fig. l is the front'view of the machine. Fig. 2 is the rear view. of thermachine. Figs. 3 and 4 are schematic cross-sections of thismachine. Fig. '5 shows the feeding rollers, Fig. 6the stretching rollers. Figs. 7 and 8 shw alternate shapes of stretchingrollers.

Essentially, this machine, in its simplest form, comprises a rectangular frame (1, Figs. 1 and 2) and two pair of rollers (2 and '3,' Fig. l; 4 and 5, Fig. 2), rotating on parallel shafts (6, 7, 8, and'9). The first pair of rollers is intended for holding the skin and forwarding it to the next pair of rollers which do the stretching. Accordingly,.the first pair ofrollers (2 and 3, Fig. 1) will be referred to as the feeding rollers, and the second pair (4 and 5, Fig. 2) as thestretching rollers. The skin, passing between each pair of rollers, will come in contact with one roller on itsflesh side-and with the other roller on its hair side. Thus, the rollers in each pair will be identified as the flesh-side roller (2 or 4) or hair-side roller (3 or respectively.

The rollers in each pair or set (consisting'of one fleshside and one hair-side roller) rotate, as shown by the arrows in Figs. 3 and 4, in opposite directions. Figs. 3 and 4 are cross-sections of the machine throughthe middle of the rollers andperpendicular to theiraxes. Fig. 3 shows the arrangement of the rollers forthe horizontal movement of the skins throughthe-machine duringthe process of stretching, Fig. 4for the'vertical movement of the skins. All flesh-side rollers rotate-in the same direction. All hair-side rollers rotate in the same direction. The rollers of each set are kept in close contact'with one another by. pressure applied to the bearings housing the respective rollers. For the sake of clearness, the rollers in each set on Figs. 5 and 6-are shown separated from each other instead of, as they should be, touching one another. Gear sprockets (10, Fig. 1,.-and*11, Fig. 2), or pulleys are attached to one or both-sides of the rollers.

The stretching action is obtained by rotating the stretching rollers (4 and 5, Fig. 2) at a peripheral speed'higher than that of the feeding rollers (2 and '3, Fig. 1). The diameterof the gears, sprockets (1 1, Figx2), or pulleys rotating the stretching rollers is smaller than-the 'diameter of the gears, sprockets (10, Fig. 1), or pulleys -rotating the feeding rollers. This causes the stretching rollers to revolve faster than the feeding rollers, thus increasing the peripheral speed of the stretching rollers. An increase in peripheral speed ratio can also be obtained by increasing the diameter of the stretching rollers as compared with the diameter of the feeding rollers, or by using motors of different speeds for each set of rollers.

In order to prevent slipping between the skin and the rollers, the latter are grooved. The feeding rollers are grooved laterally. In order that the skin could simultaneously be stretched in the direction of its movement and transversely, the grooves on the stretching rollers (4, Fig. 2) are made in the form of oppositely directed spirals or screw threads joining in the middle of the rollers. In order-not to damage the hair of the for skin or the finer grain of the leather skin, the hair-side rollers (3 and 5) are made smooth and are not being driven directly by the motor (12, Fig. 1). Instead, the gears, sprockets (10, and 11), or pulleys are attached to the flesh-side rollers only, so that the hair-side rollers revolve only on account of the pressure contact with the corresponding flesh-side rollers (2 and 4) which, alone, are being driven by the motor. The word motor implies any source of motive power capable of producing the required torque. The hair-side rollers provide the pressure necessary for the operation, without causing any appreciable friction between the rollers and the hair side of the skin.

It is preferable that the bearings of the flesh-side rollers be rigidly attached to the frame of the machine, so that the-position of the axes of those rollers remain unchanged during their operation. However, the bearings of the hair-side rollers arepermitted a little freedom of movement directly to and from the corresponding bearings of the flesh-side rollers. Thus, while the axes of all the rollers concerned remain practically parallel to each other, the aXis of each hair-side roller can be brought closer to or farther-away from the corresponding axis of the flesh-side rollerby the pressure applied to the bearings housing the shafts (7, Figs. 1 and 9, Fig. 2) of the hair-side rollers, or by the variable thickness of the skin.

The mechanism for regulating the pressure between the rollers in each set will be understood by referring to Figs. 1 and 2. The frame (1, Fig. l or 2) houses the bearings of the flesh-side rollers only. The bearings of the hair-side rollers are housed in the rectangular plates 13 which are suspended vertically from the springs 14 on either side of each set of rollers. The shafts of the flesh-side rollers (6 and 8, Figs. 1 and 2), while being supported by the bearings housed in the frame 1, pass through rectangular slits in the plates 13. The size of the slits is such, as to permit the plates to move freely, together with the hair-side rollers they house, to and from the corresponding flesh-side rollers, but not in the plane of movement of the skin between two successive sets of rollers. The shafts 7 and 9, supported by the bearings that are housed in the plates 13, also pass through rectangular slits in the frame on either end of the shafts. These slits restrict the movement of the shafts 7 and 9 in the same manner as the slits in the plates. Thus the shafts 7 and 9, while remaining in the same vertical planes with the shafts 6 and 8, respectively, can, by lifting .or lowering the plates 13, be moved closer to or farther awayfrom the shafts 6 and 8, respectively. The plates 13 are being held by the tension of the stretched springs 14 attached to the ends of the bolts 15 (Figs. 1 and 2). This upward tension on the plates is converted into pressure between the two rollers in each set. The bolts 15 (Figs. 1 and 2) pass through holes in the top of the frame. These holes are slightly larger than the diameter of the bolts. The bolts are being held in position by the threads in'the nuts 16 (Figs. 1 and 2) on top of the frame. By rotating the nuts 16, the bolts are being lifted or lowered, depending on the direction of rotation. The lifting or lowering of the bolts, in turn, regulates the tension of the attached springs 14 and the pressure between the rollers. Washers (17, Figs. 1 and 2), are placed between the frame and the nuts to facilitate the rotation of the nuts.

Cylindrical stretching rollers will provide an equal stretching force all along the line of contact with the skin. However, the toughness of the skin, from the back to the belly, varies. The skin, therefore, will stretch unevenly when subjected to a uniform stretching force. To meet this problem, the stretching rollers are made of varying diameter along the same roller. As has been pointed out above, a change in the diameter of the stretching roller will cause a corresponding change in peripheral speed at this particular point and, consequently, a change in the stretching force at this point. Thus, the part of skin, offering the biggest resistance to stretching, can be placed over the section of the roller providing the biggest stretching force. Accordingly, one stretching roller (18, Fig. 7) can be made in the form of two frustums of a right cone, joined at their bases, while the other stretching roller (M, Fig. 7) has two frustums of a right cone with the same top and base angles, joined at the tops. Instead of the above described shape, the stretching rollers can be made of any other shape embodying this principle of a varying diameter alongside the axis of the roller. For instance, one stretching roller (20, Fig. 8) has a cross-section, along its axial plane, consisting of two circular segments mounted with their bases on the opposite long sides of a rectangle; the corresponding cross-section of the other stretching roller (21, Fig. 8) consists of the same two segments scooped out of the long sides of a rectangle. The cross-sections of the two stretching rollers will appear as a convex and a concave lens, respectively, and the convex bulge of one roller will just fit into the concave depression of the other.

Thus far, only two sets of rollers were considered. However, it may sometimes prove advantageous to use more than one set of stretching rollers. The maximum amount of stretch, fixed by the ratio of peripheral speeds, is seldom attained in practice, due to some slipping of the skin between the rollers. This slipping of the skin can be minimized by increasing the number of sets of stretching rollers or by increasing the pressure between the rollers in each set. Due to the high pressure of the rollers on the skin, the ridges of the rollers may cut into the flesh side of the skin or leave there objectionable grooves. It is better in such a case to reduce the pressure between the rollers and to employ instead more than one set of stretching rollers. Each succeeding set of stretching rollers has a peripheral speed greater than that of the preceding set. The stretching is thus being increased without subjecting the skin to too great a pressure. When more than two pair of rollers are being used, each pair of rollers serves in turn to feed the skin to the next pair of rollers. A pair of smooth rollers, following the stretching rollers, may serve to smooth out the grooves on the skin, caused by the pressure of the preceding rollers.

The rollers can be set up in a way that the skin will move during stretching horizontally (Fig. 3), vertically (Fig. 4), or in any other plane. The skin, moving horizontally, will tend to droop, due to its own weight, before reaching the next pair of rollers and will, therefore, not be engaged by these rollers. Therefore, a guide (22, Fig. 3) is provided that will direct the skin to the line of contact between the next pair of rollers.

The skin might still be damp from dressing, or it is sometimes deliberately wet to obtain a greater stretch. In any event, the damp skin may have a tendency to cling to the flesh-side rollers. In order to peel off the of the operator.

4 skin from the rollers, blades (23, Figs. 3 and 4), close and tangent to the rollers, are fastened to the frame of the machine. If, under operational conditions, the peeling blade is being caught in the straight lateral grooves of the feeding roller, spiral grooves should also be used on the feeding roller.

Another method of peeling the skin off the flesh-s1de roller. The edge of the peeling blade consists of a series of narrow and shallow projections. The flesh-side roller has corresponding peripheral grooves to fit these pro jections. This permits the blade to lift the skin without itself being caught in the grooves of the roller.

When the skin is moving in a vertical plane during stretching, a guide (24, Fig. 4) is provided to enable the operator to feed the skin into the machine horizontally. The guide, which is attached above the feeding rollers, is bent into a arc. The skin is inserted from the front into the guide and is being directed by the curve of the guide right over the line of contact between the feeding rollers, as shown by the arrows inside this feeding guide. The skin is now moving downward into the feeding set of rollers. A similar discharging guide (25, Fig. 4) is placed directly below the line of contact of the last pair of rollers. The exit of the guide is directed to the front, towards the operator. Thus, as indicated by the arrows inside the discharging guide, the skin, after being stretched, is being ejected in front This arrangement enables the operator to feed the skins and receive them stretched on the same front side of the machine.

The rollers in each set must be pressed together in order for them to discharge their intended functions right. The pressure is being applied only to the bearings of the hair-side rollers in each set. Since the hairside rollers move freely to and from the corresponding flesh-side rollers, the pressure from the hair-side rollers is transmitted to the flesh-side rollers. Thus, the skin, passing between each set of rollers, is being pressed together by both rollers.

Skins, after being dressed, appear to be of different toughness, partly due to the nature of the skin, partly due to the type of dressing. The pressure on each type of skin must be adjusted so as to obtain maximum stretch without damaging the skin. For this reason, the pressure on the bearings is made adjustable. The pressure on all bearings is being controlled from one center by the operator.

The nuts 16 (Figs. 1 and 2) are, in reality, sprockets with an inside thread matching the thread of the bolts 15. All those sprockets 16 are joined by a roller chain 26. This chain is also being engaged by another sprocket 27 located in front of the operator. By rotating the sprocket 27, the chain transmits simultaneously the rotation to all sprockets 16, thus lifting or lowering the bolts 15 and varying the tension of the springs and the pressure between the rollers. A wheel 28 is mounted on the same shaft as the sprocket 27, and above it, to facilitate the rotation of the sprocket by the operator. Thus by turning this wheel 28, the operator can simultaneously regulate the pressure between all the rollers of the machine.

The rotation of the pulley 29 (Fig. 1) is transmitted to the pulley 30, on the feeding flesh-side roller, through the belt 31. 32 (Figs. 1 and 2) denotes collars intended to prevent the rollers from sliding sidewise.

I claim:

1. In a stretching machine comprising two or more pairs of pressed-together, counter-rotating rollers, each roller having a peripheral speed greater than the peripheral speed of the corresponding preceding roller, the improvement comprising only one roller in each pair being power driven and having its curved surface grooved, the second roller being smooth and free to be rotated by the drag of the material.

2. In a stretching machine comprising two or more pairs of pressed-together, counter-rotating rollers, each roller having a peripheral speed greater than the peripheral speed of the corresponding preceding roller, the improvement comprising only one roller in each pair being grooved, the second roller being smooth.

3. A method for stretching fur skins, comprising passing said skins between two or more pairs of pressedtogether counter-rotating rollers in which a roller of each pair rotates at a peripheral speed greater than the peripheral speed of the corresponding preceding roller with the flesh side of the skin positioned so that it is subjected to the stretching action of power driven grooved rollers, while the hair side of the skin, in contact with the corresponding smooth roller of each pair, moves forward freely.

References Cited in the file of this patent UNITED STATES PATENTS 1,067,164 Dobyne July 8, 1913 2,079,270 Wilson May 4, 1937 2,493,924 Mowad Ian. 10, 1950 FOREIGN PATENTS 207,777 Germany Mar. 9, 1909 226,248 Germany Sept. 30, 1910 403,027 France Sept. 15, 1909 

